Suppressive Effect of Interleukin 10 on Priming of Naive Hepatitis C Virus–Specific CD8+ T Cells

Growing evidence suggests a role for the immunomodulatory cytokine interleukin-10 (IL-10) in hepatitis C virus (HCV)specific CD8 T-cell failure. To address the possible role of IL-10 during priming, we performed in vitro priming experiments with naive HCV-specific CD8 T cells and autologous monocyte-derived dendritic cells in the absence or presence of IL-10. Our results showed that IL-10, when present during priming, significantly reduced the frequency of HCV-specific CD8 T cells after coculture; It was directly targeting CD8 T cells and led to impaired effector cell differentiation. These results may provide a possible mechanistic basis for the association between early IL-10 elevation, T-cell failure, and viral persistence.